Traffic congestion prediction in a conventional floating car system has been performed in such a manner that only pieces of information on current positions of floating cars are collected, and based on these pieces of information on the current positions, present traffic congestion information is generated and traffic congestions are predicted. As an example using such floating cars, there is a technique disclosed in Patent Document 1 as below.
[Patent Document 1] Japanese Patent Application Publication No. 2003-151085 (Abstract)